In plants, ammonium is first assimilated into the amino acids L-Gln and L-glutamate and then channeled into L-aspartate and L-Asn. These amino acids serve as nitrogen donors in biosynthetic reactions, as well as compounds for intercellular nitrogen transport. In amide-transporting plants, Asn can act as the sole nitrogen source for the growth of plant tissues. In higher plants the catabolism of Asn is thought to occur mainly through two routes. The first pathway involves the hydrolysis of Asn… CONTINUE READING